In recent years, advances in aortic surgery have led to the use of stent grafts in the treatment of aortic disease. Stent grafts may be used in the treatment of aortic dissecting aneurysms, aortic true aneurysms, aortic pseudoaneurysms, aortic penetrating ulcers, etc. The application of this technique greatly reduces the mortality compared to conventional operative treatments, greatly reduces the occurrence of postoperative complications, minimizes operation incisions, and insures a more rapid recovery for the patient. Using the treatment of aneurysm as an example, the stent graft is expanded after being placed at the location of the lesion in order to isolate the tumor body from the blood. This eliminates the risk of death caused by massive hemorrhaging due to the rupture of the aneurysm, and also prevents tissue and organs from being compressed by the tumor body. Several products are already presently being used at home as well as abroad, for example Talent, AneuRex, Exclude, Relay, Gore, etc., abroad, and Hercules, Aegis, Ankura, etc. at home.
However, most of the above products are in a straight cylindrical shape, and have no branches at proximal ends thereof to assist in anchoring, and thus can only perform positioning using the bare segment, the small wave segment and the large wave segment in the main body. Therefore, the above products need enough anchoring distance. Otherwise, a risk of stent shift down and endoleak will be produced. Thereby, the above products are only adapted to the descending thoracic aortic aneurysm, and usually require a normal thoracic aortic aneurysm wall where the aneurysm or the tear is at least 15 mm away from the left subclavian artery. With respect to the cases of the dissection or aneurysm involving the left subclavian artery, a left subclavian artery bypass surgery is generally performed, and then the above stent graft is applied to treat the aneurysm or dissection rupture. However, such a method still causes comparatively high endoleak complications. With respect to the patients having the dissection or the aneurysm which involves the range from the ascending aortic aneurysm to the left common carotid artery, no available stent graft exists at present, and a conventional operative treatment method is still employed.
The design and use of the stent graft with a branch may be able to eliminate the need for conventional operative treatments. The main body portion and the branch portion of the stent can be respectively used for repairing the lesions in the aorta and the branch artery. CN201131823Y discloses an endovascular stent with a branch, where the stent segments of the main body and the branch of the stent are single in structure and cannot be adapted to diversified blood vessel shapes. CN101015478A also discloses a branched stent graft, where the branch portion of the stent is connected with the main body portion via a flexible connecting part, and the main body portion and the branch portion are respectively used for the aorta and the left subclavian artery. This stent graft can ensure blood supply to the aorta and the left subclavian artery at the same time; however, if the release of the proximal flexible connecting part of the branch is unfavorable (e.g., distorted or folded), the left subclavian artery will be blocked. Accordingly, the above stent grafts with a branch in the prior art have a limited application range and can generally only be used for lesions in the left subclavian artery, while doing nothing for lesions in the bow and the ascending aorta or lesions involving multiple branches.